21202232201221 has 16 divisors (see below), whose sum is σ = 22338878284800. Its totient is φ = 20067663007728.

The previous prime is 21202232201197. The next prime is 21202232201237. The reversal of 21202232201221 is 12210223220212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21202232201221 - 2¹¹ = 21202232199173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202232201192 and 21202232201201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202235201221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 313520550 + ... + 313588168.

It is an arithmetic number, because the mean of its divisors is an integer number (1396179892800).

Almost surely, 2^{21202232201221} is an apocalyptic number.

It is an amenable number.

21202232201221 is a deficient number, since it is larger than the sum of its proper divisors (1136646083579).

21202232201221 is a wasteful number, since it uses less digits than its factorization.

21202232201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82728.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21202232201221 its reverse (12210223220212), we get a palindrome (33412455421433).

The spelling of 21202232201221 in words is "twenty-one trillion, two hundred two billion, two hundred thirty-two million, two hundred one thousand, two hundred twenty-one".